Table 1.
Demographic and clinical characteristics of patients at baseline
| Characteristic | Age group | Total | ||
| < 60 years | 60 to 64 years | > 64 years | ||
| Cases | ||||
| Total | 3,160 (100) | 645 (100) | 422 (100) | 4,227 (100) |
| Receptor status (ER-positive and/or PgR-positive versus both negative) | ||||
| Positive | 1,941 (61.4) | 447 (69.3) | 278 (65.9) | 2,666 (63.1) |
| Negative | 876 (27.7) | 144 (22.3) | 112 (26.5) | 1,132 (28.6) |
| Unknown | 343 (10.9) | 54 (8.4) | 32 (7.6) | 429 (10.1) |
| Tumor grading | ||||
| Grade 1 | 142 (5.1) | 29 (5.0) | 22 (5.8) | 193 (5.2) |
| Grade 2 | 1,534 (54.9) | 321 (55.6) | 224 (59.4) | 2,079 (55.5) |
| Grade 3 | 1,117 (40.0) | 227 (39.3) | 131 (34.7) | 1,475 (39.4) |
| Valid | 2,793 (88.4) | 577 (89.5) | 377 (89.3) | 3,747 (88.6) |
| Missing | 367 (11.6) | 68 (10.5) | 45 (10.7) | 480 (11.4) |
| Histological tumor type | ||||
| Ductal invasive | 2,405 (76.1) | 459 (71.1) | 315 (74.6) | 3,179 (75.2) |
| Lobular invasive | 477 (15.0) | 127 (19.6) | 65 (15.4) | 669 (15.8) |
| Other | 233 (7.3) | 54 (8.3) | 35 (8.2) | 322 (7.6) |
| Valid | 3,115 (98.6) | 640 (99.9) | 415 (98.4) | 4,170 (98.7) |
| Missing | 45 (1.4) | 5 (0.1) | 7 (1.6) | 57 (1.3) |
| Surgery type | ||||
| Breast-conserving | 1935 (61.2) | 381 (59.0) | 228 (54.0) | 2,544 (60.1) |
| Mastectomy | 961 (30.4) | 216 (33.4) | 161 (38.1) | 1,338 (31.6) |
| Valid | 2,896 (91.6) | 597 (92.5) | 389 (92.1) | 3,882 (91.8) |
| Missing | 264 (8.3) | 48 (7.4) | 33 (7.8) | 345 (8.1) |
| Age median (years) | 47 | 62 | 67 | 51 |
| Age range (years) | 23 to 59 | 60 to 64 | 65 to 80 | 23 to 80 |
Data presented as n (%). All percentage values are valid. ER, estrogen receptor; PgR, progesterone receptor.